Craftsman mower cold starting issues.

ctown75 · Dec 24, 2008

Well I have this mower, it's 6 or 7 years old. It's only a 42" cut and we mow 2+ acres with it in the summer, plus it used to have a plow on it so it sees plenty of hours year round. It has been a rough starting mower when it's cold out since I got it 4 years ago. This year I finally got fed up with jump starting it because when the hose freezes I use the tractor to take water out to my animals. So I replaced the battery with a bigger one. It had the original battery, which was unmarked, but it still tested good and had no issues starting it when warm outside, even after sitting a week or so. I put a new one in that is 350 cca- the biggest mower battery I could find. Still no cold starts. I took all the terminals off the battery, solenoid, and starter, and cleaned them with a wire brush- still nothing! So I got fed up(see the trend? LOL) and put my car booster on it(a big roll away charger, puts out 150 amps on boost) and started it. The first couple days it started, but then a couple days ago it was uber cold and I layed starter a little bit, and the starter started smoking. So I took it apart to find the brushes trashed. Not surprising, this mower has a buttload of hours. So I bought a new aftermarket starter(AEM brand) from a local mower guy. Same story different day. still no cold starts. Is my motor wearing down to where it is just that hard to start(I can still turn it by hand fairly easily) Or am I missing something? I think I already trashed the new starter. I am running a little thicker oil than recomended(15w-40). It is 18HP single cylinder, briggs and stratton, intek I/C with "AVS"(anti vibration sys). Any help or advice is appreciated!

Thanks and Merry Christmas!
Scott

dqdave1 · Dec 24, 2008

Check your battery cables for resistance, they may be old and are bad. Check ground connections at battery and on Frame. Remove spark plug; does it crank then? Check voltage at starter connection. Check voltage at key switch.

bbirder · Dec 24, 2008

Might try setting the valves. Some of these engines use the valve settings to activate the decompression on starting. Other than that or a bad plug or wire, it may have worn rings and low compression.

ctown75 · Dec 24, 2008

cables all seem good, ends clean and solid. I pulled the plug and it did not want to roll. So i put the old starter back on, and with the plug still it out, it roll perfect. I then put the plug back in and it started up fine and easily to boot. I am going to take the new starter back to the guy because he said it warranties up to a year, I've only had it two months. I can't see where a bad plug or wire would/could cause the motor not to roll over, but the valve issue makes sense if this is one of these motors. It is definitely hanging up on the compression stroke, and it has done this since I have owned it, so if it were a ring/bearing/cylinder issue I would imagine it would have shown more serious symptoms after the additional 500+ hours it has seen. It is acting just the same as it did when I first got it, no better, no worse. I just depend on it a little more these days when the weather is poor, so I am trying to tame the beast- LOL.

dqdave1 · Dec 24, 2008

Make sure battery cables are good; they may look good but have high resistance. Make sure starter is grounded well as negative wire is to frame and engine to frame is not as good as it should be.

Dennisfly · Dec 24, 2008

I think it would be prudent to run thinner oil. I don't know what the manufacturer recommends, but I would be thinking more like 5w/30 for winter in Ohio. This probably isn't the whole problem, but it may make starters and the engine last longer.

dqdave1 · Dec 25, 2008

I agree; heat up engine; change oil to 5w - 30

ray66v · Dec 25, 2008

I did not see what you mean by not starting. Is it cranking, and not firing? Or, is it not cranking at all, or very slowly?

Worn engines that crank but will not fire, usually do so because of lost compression. Though some have a fuel pump, (could be the problem if you do). The fuel systems usually rely on suction to pull the gas from the carburetor. This, plus a choke that does not close all the way, or in the case of newer systems where there is no choke, creates lots of cold start issues.

Remove the air cleaner, and using a gloved hand to seal the opening, (if this can be done safely), while cranking, did it fire up that way? Then, choke is not closing all the way. Next, try a shot of ether, or WD 40 in the opening, choke with your hand and see if it fires. This working, will suggest fuel and or choke issues. Neither test working? check for spark issues. Fuel lines are failing at a high rate due to ethanol.

If its not cranking; battery, battery cables, starter, solenoid, and or switch, all could be the problem. Many people use those bolt on battery cable replacement ends, DON'T! The cable corrodes inside where it clamps on and the connection fails, even though it "looks" fine. Do you have one of those on there? Replace the cable if so. Check to see if your ground is still good, or has it corroded? Bypass the solenoid to see if it, is the trouble. Jump the terminals to see it the switch is bad.

Merry Christmas.

ctown75 · Dec 26, 2008

Dqdave- I will dig out my ohm meter and check it out. at about 25* today it started fine with the old starter. I left the trickle charger on overnight to make sure it was fully charged, and it roll and started like new. I am now wondering if the new starter was garbage and my whole issue was too weak a battery the whole time- I didn't put the bigger cca battery in until after the new starter was in. The starter grounds to the motor and the motor to the frame, the only ground is from frame to battery, and it looks good. I did clean up both sides of all wire connections again with wire brush.

Dennis fly- I think the mfg recommends 10w-30. The heavier oil was the only thing I could think of non electrical that was holding it up aside from a catastrophic failure. This does seem linked directly to outside temperature.

Dqdave again- I thought about getting a heating pad or something for it. Jegs sells self adhesive ones for race engine pre heaters, as well as an oil preheater designed for aluminum oil pans- this does however require major modification(a hole in the block somewhere to put the heater through) this would probably work better but I don't know about doing that to it. The heating pad just sticks to the block. TSC sells a magnetic one, but with an aluminum block I don't think that is the best way to go.

ray66v- check out all the posts, i clearly am talking about issues with getting the motor to roll. Once i get it to roll, it starts fine. It's not choke related, the choke works as it should and closes fully. starting fluids don't help when the motor won't roll. motor is clearly hanging up on compression stroke(when it hangs up) I can, however, put my hand on the flywheel guard and fairly easily turn the motor through that stroke, and then it will roll via the starter and hang up again on the compression stroke. There is most definitely compression with in the motor.

dqdave1 · Dec 26, 2008

I do not think you will have a problem with 5w- 30 oil. I believe it will help you alot in cold weather. Synthetics are great for cold starts also. My diesel saw a tremendous difference in cold weather cranking with synthetic. 15w oil in cold weather probably not good on engine while cold as it is not lubing as good as it should being thick. Make sure engine to frame bolts are tight to get grounding potential to starter. ( ground from battery is to frame) ENgine also must be grounded to frame. ( normally through bolts that connect it to frame) Have seen loose bolts that don't allow a good connection.

Probably a bad starter as you mentioned. Hope it has straightened out for you.

bbirder · Dec 26, 2008

Again, I think your valves need adjusting. Check out the thread at this website.

help! craftsman mower, with 16hp-ohv b&s engine starting problem - Tractors Forum - GardenWeb

ctown75 · Dec 26, 2008

I don't think that directly relates to my issue. Mine will easily start after you start it the first time for the day. you can get it nice and hot and shut it down and it fires right back over and does not even hesitate. Also, mine starts very easily in fair to warm weather. The motor will roll very easily all the time, unless it has sat for a good period of time (at least overnight- probably because of the tendency to be colder at night) in cold weather. It can sit for 2 hours and start right back up. Plenty of time for it to cool down almost completely. I will check the valves out however to at least rule them out, if not find the issue. Thanks!

ctown75 · Dec 28, 2008

I bought some mobil 5w30 ful synthetic- what the manual recommends for cold weather operation. Also got a new plug, oil filter, pre/air filter, fuel filter. I am going to inspect(and adjust as necessary) the valves. I will update with what I find, if anything.

bbirder · Dec 28, 2008

Scott,
One other thing to check. Does your carb have a wire coming from the bottom of it. If so,this is an electric cutoff switch for the gas. If this is leaking, it will allow some gas to leak into the cylinder when stopped. On cold starts this liquid gas will not compress and cause the engine to lock.After you rock it over by hand or try long enough it will then turn over. This can also dilute your oil. Does your oil smell like gas? Have you noticed a wet muffler or fuel tank going down. Just another thought.

ctown75 · Dec 28, 2008

Ok I changed oil to 5w30 full syn and changed the oil filter- the air filter and the fuel filter too. I adjusted the valves. Very simple for anyone thinking about it(easier than changing the starter LOL) There seemed to be a lot of slack in them. My feeler guages start at .005 so i made the intake real snug on that and the exhaust I put at .006. I wouldn't have said the motor had a knock or valve tick before, but the motor sure is quieter now! Now, only tonight will tell if the motor starts easier. It's going to 25* tonight, plenty enough to make it start very hard before. I will update with the progress.

ctown75 · Dec 28, 2008

bbirder said:
Scott,
One other thing to check. Does your carb have a wire coming from the bottom of it. If so,this is an electric cutoff switch for the gas. If this is leaking, it will allow some gas to leak into the cylinder when stopped. On cold starts this liquid gas will not compress and cause the engine to lock.After you rock it over by hand or try long enough it will then turn over. This can also dilute your oil. Does your oil smell like gas? Have you noticed a wet muffler or fuel tank going down. Just another thought.

tank holds fuel fine- and oil did not smell like gas as of today.